Butterfly knife



FIG. 1 is a right hand facing perspective view of a butterfly knife;

FIG. 2 is a left hand facing perspective view of the butterfly knife shown in FIG. 1;

FIG. 3 is a right hand facing side view of the butterfly knife shown in FIG. 1;

FIG. 4 is a left hand facing side view of the butterfly knife shown in FIG. 1;

FIG. 5 is a right hand facing top view of the butterfly knife shown in FIG. 1;

FIG. 6 is a right hand facing bottom view of the butterfly knife shown in FIG. 1;

FIG. 7 is a front end view of the butterfly knife shown in FIG. 1;

FIG. 8 is a rear end view of the butterfly knife shown in FIG. 1;

FIG. 9 is a right hand facing side view of the butterfly knife shown in FIG. 1 that is in the half open position; and,

FIG. 10 is a right hand facing side view of the butterfly knife shown in FIG. 1 that is in the closed position. 

CLAIM The ornamental design for a butterfly knife, as shown and described. 